the speedometer on my car stop working on 1996 Honda Accord

the speedometer on my car stop working and the check engine light is on and i had a oil leak and i showed to couple of mechanics and got the check engine code and it says emission leak or loose gas cap .....no one can come up with right solution for it .wonder if someone can help me find out the problem .

The Speedometer issue may be the output speed sensor, check for this as well. If you tell me what the EVAP codes is then I can help you. I do Emissions work in CA and have written a bunch of EVAP trouble code code articles for RepariPal. like http://repairpal.com/OBD-II-Code-P0442